Topical administration of the single-chain anti-TNFα antibody DLX105 suppresses TNFα and Th17 cytokines in psoriatic skin Athanasios Tsianakas1*, Patrick Brunner2*, Kamran Ghoreschi3, Claudia Berger4, Karin Loser1, Martin 3 2 1 4 Röcken , Georg Stingl , Thomas Luger , Thomas Jung Dept. of Dermatology, Univ. Münster, Germany, 2 Dept. of Dermatology, DIAID, Med. Univ. Vienna, Austria, 3 Dept. of Dermatology, Univ. Tübingen, Germany, 4 Delenex Therapeutics AG, Zürich, Switzerland; * these authors equally contributed to this work 1 ______________________________________________________ Introduction While systemically administered anti-TNFa antibodies are effective in treating chronic plaque psoriasis, it is not clear whether these drugs need to act systemically, within the secondary lymphatic tissues, or whether inhibition of skin-produced TNFa would be sufficient to mediate a clinical response. To answer this question, we conducted two clinical trials in psoriatic patients and administered the novel single-chain antibody DLX105 intra-dermally (Phase 1b) or topically (Phase 2) directly to psoriatic plaques. Intradermal injection of DLX105 – Phase 1 A multi-center, double-blind, randomized, placebocontrolled, intra-individual comparison, phase 1b study to evaluate the safety, tolerability and pharmacokinetics of intra-dermal injections of DLX105, a single-chain (25kDa) anti-TNF-a antibody, into lesional skin in patients with mild-tomoderate psoriasis vulgaris. Efficacy & Biomarkers In skin biopsies, taken at day 14 from placebo- and DLX105 treated plaques, mRNA levels of pro-inflammatory molecules were profoundly decreased as compared to placebo. As previously shown, DLX105 was clinically efficacious, had an excellent safety profile and was well tolerated when administered intra-dermally (The single-chain anti-TNF-alpha antibody DLX105 induces a clinical response in psoriasis patients when administered intra-dermally, Patrick Brunner, Athanasios Tsianakas, Claudia Berger, Georg Stingl, Thomas Luger, Thomas Jung, Arbeitsgemeinschaft Dermatologische Forschung, Cologne, March 2014). Results – Phase 1 B Fold increase over healthy skin (mRNA expression levels) A (A) At day 14, the higher dose of DLX105 (filled circles) induced a mean local PASI decrease of 33% over baseline, whereas the placebo response (open circles) was 12% (p=0.002). While 3 out of 10 patients showed a placebo response, 9 out of 10 patients showed a drug response (data not shown). Early studies with systemic infliximab and ustekinumab tretament reported similar changes from baseline in the range of 30 to 40%. On average, serum levels of DLX105 were in the range of 50ng/mL (data not shown). (B) At day 14, skin biopsies were taken from placebo- and DLX105-treated plaques. Levels of cytokine mRNA were normalized against healthy volunteer skin. Data from 15 subjects were available, differences to placebo were *p<0.05 (paired t-test) for each cytokine investigated except for TNFa. We did not observe significant clinical changes upon DLX105 topical treatment. This might be partially due to a later onset of action as known from other anti-psoriatic treatments. Tape stripping No tape stripping __________________________ Topical application of DLX105 – Phase 2 Pharmacokinetics and Immunogenicity DLX105 serum levels could not be detected at any of the four time points during the course of the study (predose at Days 1, 15, 29 and 43) One patient exposed to DLX105 had no detectable anti-DLX105 antibodies (<10ng/ml) at baseline in serum and had 24 ng/ml anti-DLX105 antibodies at end of study (week 6) Summary Double-blind, randomized, placebo-controlled study with 2 treatment arms (parallel groups): Patients were randomized to either 0.5% DLX105 topical formulation (n=27) or placebo (n=27). Two plaques per patient were identified for treatment. One of these plaques was selected for tape stripping on a weekly basis to further increase drug penetration into the skin. Study drug was administered twice a day over 4 weeks on both plaques. Results – Phase 2 Safety and Tolerability There were no serious adverse events reported; AE were in the same range in the DLX105 and in the placebo treated patients. • Our data indicate that locally-administered DLX105 sufficiently inhibits skin-derived TNFa in a way that biological down-stream effects are detectable, i.e. on the Th17 pathway • The translation of these biological effects into a meaningful clinical response is dependent on the concentration of locally-deposited DLX105 and most likely requires improved penetration into deeper dermis • Local tolerability and systemic safety are excellent, DLX105 has a low potential for immunogenicity and systemic exposure is either low or absent • DLX105 having a IC50 of 300 pM in the formulation used was able to show a proof-of-principle of PENTRA®Body-mediated local treatment • Longer treatment periods (as is the case for etanercept), increasing drug concentration in the dermis by biological, chemical or physical methods and/or a more potent follow-on anti-TNFa PENTRA®Body might result in clinical efficacy